21003261798394 has 4 divisors (see below), whose sum is σ = 31504892697594. Its totient is φ = 10501630899196.

The previous prime is 21003261798377. The next prime is 21003261798403. The reversal of 21003261798394 is 49389716230012.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 17076622317769 + 3926639480625 = 4132387^2 + 1981575^2 .

It is a super-2 number, since 2×21003261798394² (a number of 27 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5250815449597 + ... + 5250815449600.

Almost surely, 2^{21003261798394} is an apocalyptic number.

21003261798394 is a deficient number, since it is larger than the sum of its proper divisors (10501630899200).

21003261798394 is a wasteful number, since it uses less digits than its factorization.

21003261798394 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10501630899199.

The product of its (nonzero) digits is 3919104, while the sum is 55.

The spelling of 21003261798394 in words is "twenty-one trillion, three billion, two hundred sixty-one million, seven hundred ninety-eight thousand, three hundred ninety-four".